Width of the fetal lateral ventricular atrium between 10 and 12 mm: a simple variation of the norm?

Fetal macrocephaly: Pathophysiology, prenatal diagnosis and management

Macrocephaly means a large head and is defined as a head circumference (HC) above the 98th percentile or greater than +2SD above the mean for gestational age. Macrocephaly can be primary and due to increased brain tissue (megalocephaly), which in most cases is familial and benign or secondary. The latter may be due to various causes, including but not limited to communicating or non-communicating hydrocephalus, cerebral edema, focal and pericerebral increased fluid collections, thickened calvarium and brain tumors. Megalocephaly can be syndromic or non-syndromic. In the former, gyral and structural CNS anomalies are common. It is important to exercise caution when considering a diagnosis of megalocephaly due to limitations in the accuracy of HC measurement, lack of nomograms for specific populations, inconsistencies between prenatal and postnatal HC growth curves and progression over time. The degree of macrocephaly is important, with mild macrocephaly ≤2.5SD carrying a good prognosis, especially when one of the parents has macrocephaly and normal development. Cases in which the patient history and/or physical exam are positive or when parental HC are normal are more worrisome and warrant a neurosonogram, fetal MRI and genetic testing to better delineate the underlying etiology and provide appropriate counseling.

Hippocampal rotation is associated with ventricular atrial size

BACKGROUND

Fetal ventriculomegaly is a source of apprehension for expectant parents and may present prognostic uncertainty for physicians. Accurate prenatal counseling requires knowledge of its cause and associated findings as the differential diagnosis is broad. We have observed an association between ventriculomegaly and incomplete hippocampal inversion.

OBJECTIVE

To determine whether ventricular size is related to incomplete hippocampal inversion.

MATERIALS AND METHODS

We retrospectively evaluated pre- and postnatal brain MRIs in normal subjects (mean GA, 31 weeks; mean postnatal age, 27 days) and patients with isolated ventriculomegaly (mean GA, 31 weeks; mean postnatal age, 68 days) at a single academic medical center. Lateral ventricular diameter, multiple qualitative and quantitative markers of hippocampal inversion, and evidence of intraventricular hemorrhage were documented.

RESULTS

Incomplete hippocampal inversion and ventricular size were associated in both normal subjects (n=51) and patients with ventriculomegaly (n=32) (P<0.05). Severe ventriculomegaly was significantly associated with adverse clinical outcome in postnatal (P=0.02) but not prenatal (P=0.43) groups. In all additional cases of isolated ventriculomegaly, clinical outcome was normal over the time of assessment (mean 1±1.9 years; range 0.01 to 10 years).

CONCLUSION

Lateral ventricular atrial diameter and incomplete hippocampal inversion are associated. Less hippocampal inversion correlates with larger atria. For every 1-mm increase in fetal ventricular size, the odds of incomplete hippocampal inversion occurring increases by a factor of 1.6 in normal controls and 1.4 in patients with ventriculomegaly.

White matter changes in fetal brains with ventriculomegaly

Introduction

Ventriculomegaly (VM) is a fetal brain malformation which may present independently (isolated form) or in association with different cerebral malformations, genetic syndromes or other pathologies (non-isolated form).

Methods

This paper aims to study the effect of ventriculomegaly on the internal tridimensional architecture of fetal brains by way of Klingler's dissection. Ventriculomegaly was diagnosed using fetal ultrasonography during pregnancy and subsequently confirmed by necropsy. Taking into consideration the diameter of the lateral ventricle (measured at the level of the atrium), the brains were divided into two groups: moderate ventriculomegaly (with atrial diameter between 13 and 15 mm) and severe ventriculomegaly (with atrial diameter above 15 mm).

Results and discussion

The results of each dissection were described and illustrated, then compared with age-matched reference brains. In the pathological brains, fascicles in direct contact with the enlarged ventricles were found to be thinner and displaced inferiorly, the opening of the uncinate fasciculus was wider, the fornix was no longer in contact with the corpus callosum and the convexity of the corpus callosum was inverted. We have studied the prevalence of neurodevelopmental delay in children born with ventriculomegaly in the literature and discovered that a normal developmental outcome was found in over 90% of the mild VM cases, approximately 75% of the moderate and 60% in severe VM, with the correlated neurological impairments ranging from attention deficits to psychiatric disorders.

Comparison of fetal and neonatal sonographic measurements of ventricular size in second- and third-trimester fetuses with or without ventriculomegaly: cross-sectional three-dimensional ultrasound study

OBJECTIVES

To assess, in a population comprising normal fetuses and fetuses with primary or post-hemorrhagic ventriculomegaly, the reproducibility of measurement of neonatal ultrasound indices in the fetus and to compare the performance of various cut-offs of these parameters to diagnose ventriculomegaly and classify its severity.

METHODS

This was a retrospective cross-sectional study including 182 singleton fetuses assessed by transvaginal neurosonography. The sample populations included 116 normal fetuses and 66 fetuses with primary (n = 56) or post-hemorrhagic (n = 10) ventriculomegaly. In all cases, the atrial width (AW) was measured according to standard protocols and the findings were compared with four sonographic indices developed in the neonate: the anterior horn width (AHW), the ventricular index (VI), the thalamo-occipital distance (TOD) and the fronto-occipital horn ratio (FOHR). Reproducibility of measurements was assessed using the intraclass correlation coefficient (ICC) and diagnostic accuracy of the neonatal indices was assessed against AW using areas under the receiver-operating-characteristics curves (AUC).

RESULTS

The intra- and interoperator reproducibility of measurement of AW and the neonatal measurements was excellent, with ICCs > 0.99 for all measures. The association in the fetus of all four variables developed in the neonate with the degree of ventriculomegaly as defined by the AW was strong for severe ventriculomegaly (AW > 15.0 mm; all AUC > 0.95), whereas the separation of cases with mild ventriculomegaly (AW, 10.0-15.0 mm) from those with normal AW (< 10.0 mm) was less effective.

CONCLUSIONS

When applied in the fetus, all four indices of ventriculomegaly developed in neonates (AHW, VI, TOD, FOHR) were associated strongly with fetal AW when the AW measurement indicated severe fetal ventriculomegaly. However, for mild ventriculomegaly, the association was weaker, probably due to the fact that, in the fetus, mild ventriculomegaly is not caused by obstruction of the ventricular system. Considering the similar performance of the four neonatal variables and the technical issues involved in determination of TOD and FOHR in the fetus, use of VI and AHW is preferred. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Role of prenatal magnetic resonance imaging in fetuses with isolated severe ventriculomegaly at neurosonography: A multicenter study

OBJECTIVE

The aim of this study was to report the rate of additional anomalies detected exclusively at prenatal magnetic resonance imaging (MRI) in fetuses with isolated severe ventriculomegaly undergoing neurosonography.

METHOD

Multicenter, retrospective, cohort study involving 20 referral fetal medicine centers in Italy, United Kingdom, Spain and Denmark. Inclusion criteria were fetuses affected by isolated severe ventriculomegaly (≥15 mm), defined as ventriculomegaly with normal karyotype and no other additional central nervous system (CNS) and extra-CNS anomalies on ultrasound. In all cases, a multiplanar assessment of fetal brain as suggested by ISUOG guidelines on fetal neurosonography had been performed. The primary outcome was the rate of additional CNS anomalies detected exclusively at fetal MRI within two weeks from neurosonography. Subgroup analyses according to gestational age at MRI (<vs ≥ 24 weeks of gestation) and the laterality of ventriculomegaly (unilateral vs bilateral) were also performed. Univariate and multivariate logistic regression analysis was used to analyze the data.

RESULTS

187 fetuses with a prenatal diagnosis of isolated severe ventriculomegaly on neurosonography were included in the analysis. Additional structural anomalies were detected exclusively at prenatal MRI in 18.1% of cases. When considering the type of anomaly, malformations of cortical development were detected on MRI in 32.4% cases, while midline or acquired (hypoxemic/hemorrhagic) lesions were detected in 26.5% and 14.7% of cases, respectively. There was no difference in the rate of additional anomalies when stratifying the analysis according to either gestational age at MRI or laterality of the lesion. At multivariate logistic regression analysis, the presence of additional anomalies only found at MRI was significantly higher in bilateral compared versus unilateral ventriculomegaly (OR: 4.37, 95% CI 1.21-15.76; p = 0.04), while neither maternal body mass index, age, severity of ventricular dilatation, interval between ultrasound and MRI, nor gestational age at MRI were associated with the likelihood of detecting associated anomalies at MRI.

CONCLUSION

The rate of associated anomalies detected exclusively at prenatal MRI in fetuses with isolated severe ventriculomegaly is lower than previously reported, but higher compared to isolated mild and moderate ventriculomegaly. Fetal MRI should be considered as a part of the prenatal assessment of fetuses presenting with isolated severe ventriculomegaly at neurosonography.

Neurodevelopmental outcomes in mild and moderate isolated ventriculomegaly originating in utero

OBJECTIVE

To determine the differences in outcomes between mild and moderate isolated ventriculomegaly (IVM).

METHODS

We conducted a prospective cohort study on 94 fetuses with IVM and evaluated the neurodevelopmental outcomes at 12 months of age using the ASQ-3 and BSID-I neurodevelopmental assessment tools. Progression of VM was defined as an increase in the width of the ventricular by at least 3 mm during sequential ultrasound monitoring. The population was divided into two groups according to ventricular width: mild (10-12 mm) and moderate (12.1-15 mm), which were further evaluated for VM progression in utero separately.

RESULTS

Neurodevelopmental assessments at 12 months were the main form of evaluations. Neurodevelopmental impairment (NDI) was defined as a mental development index (MDI) or psychomotor development index (PDI) < 85. There were no significant differences in NDI values between the mild and moderate groups (p = .155). Compared with the non-in utero progression group (7.6%), the rate of NDI was significantly higher (p = .004) in the group with progression (33.3%). Using linear regression and correlation, no negative correlation was found between the maximum value of atrial diameter (AD) in utero and the PDI (r = -0.021, p = .914) or MDI (r = -0.073, p = .703) score. However, the maximum change in the AD in utero was negatively correlated with both PDI (r = -0.460, p = .011) and MDI (r=-0.422, p = .020) scores.

CONCLUSION

There were likely no differences in neurodevelopmental outcomes between mild and moderate IVM. In fetuses with mild to moderate VM, intrauterine progression may be a poor prognostic factor for neurodevelopmental outcomes.

Prenatal ventriculomegaly: natural course, survival, and neurodevelopmental status

OBJECTIVE

Prenatal ventriculomegaly is classified as mild, moderate, or severe based on the atrium diameter. The natural course and intrauterine progression of mild and moderate ventriculomegaly associated with the neurodevelopmental status of these children has been widely reported.

METHODS

One hundred twenty-two pregnancies with mild and moderate ventriculomegaly referred to the pediatric neurosurgery clinic of Children's Medical Center between 2010 and 2018 were retrospectively studied. The authors collected demographic and first and sequential ultrasonographic information, associated abnormalities, information about pregnancy outcomes, and the latest developmental status of these children according to Centers for Disease Control and Prevention criteria by calling parents at least 1 year after birth.

RESULTS

The mean gestational age at the time of diagnosis was 29.1 weeks, and 53% of fetuses were female. The width of the atrium was registered precisely in 106 cases, in which 61% had mild and 39% had moderate ventriculomegaly. Information on serial ultrasound scans was collected in 84 cases in which ventriculomegaly regressed in 5, remained stable in 67, and progressed in 12 patients. Fourteen cases (29.7%) in the mild ventriculomegaly group and 6 cases (16.2%) in the moderate group had associated abnormalities, with corpus callosum agenesis as the most frequent abnormality. The survival rate was 80% in mild and 89.4% in moderate ventriculomegaly. Considering survival to live birth and progression of the ventriculomegaly, the survival rate was 100% in regressed, 97% in stable, and 41.6% in progressed ventricular width groups (p < 0.001). Neurodevelopmental status was evaluated in 73 cases and found to be normal in 69.8% of the cases; 16.4% of children had mild delay, and 5.4% and 8.2% of cases were diagnosed with moderate and severe delays, respectively.

CONCLUSIONS

In spite of a high rate of missed data in our retrospective study, most patients with mild or moderate ventriculomegaly had a stable or regressed course. Most cases had near-normal developmental status. Prospective studies with a larger sample size and detailed developmental evaluation tests are needed to answer the questions related to the natural course, survival, and prognosis of prenatal ventriculomegaly.

Estimating cerebral venous oxygenation in human fetuses with ventriculomegaly using quantitative susceptibility mapping

RATIONALE AND OBJECTIVES

The goal of this study was to estimate venous blood oxygen saturation (SvO2) in the superior sagittal sinus (SSS) in fetal brains with ventriculomegaly (VM) using quantitative susceptibility mapping (QSM).

MATERIALS AND METHODS

A radiofrequency spoiled gradient echo sequence was used to evaluate data on 19 fetuses with VM (gestational age(GA): median = 29.9 weeks (range 23 to 37.3 weeks)) and 20 healthy fetuses (GA: median = 30.9 (range 22.7 to 38.7 weeks)) at 1.5 T. Susceptibility weighted images encompassing the entire fetal brain were acquired within 1 min. An iterative, geometry constraint-based thresholded k-space division algorithm was used for generating QSM data of the fetal brain. The venous oxygen saturation was calculated using the magnetic susceptibility of the SSS obtained from the QSM data. Mixed-model analysis of variance and interobserver variability assessment were used to analyze the results.

RESULTS

The median SvO2 values in the entire VM cohort as well as for second and third trimester fetuses (with interquartile range) were: 67.8% (63.2%, 73.6%), 73.1% (69.1%, 77.3%) and 63.8% (59.4%, 68.1%), respectively. The corresponding median SvO2 value in the healthy control group was: 65.3% (58.3%, 68.2%), 67.5% (61.7%, 69.2%) and 60.8% (53.6%, 68.2%), respectively. However, the difference of SvO2 between VM and control groups was not significant at the p = 0.05 level (p = 0.076). The SvO2 was found decreasing significantly with GA in the healthy control group (p < 0.05).

CONCLUSIONS

We report for the first time the estimation of cerebral SvO2 in human fetuses with VM using QSM. This measure of oxygen saturation might be beneficial in assessing and monitoring the metabolic status of the fetus in various clinical conditions.

Sonographic spectrum and postnatal outcomes of early-onset versus late-onset fetal cerebral ventriculomegaly

OBJECTIVES

To review the prenatal characteristics and postnatal outcomes of Early-onset and Late-onset cerebral ventriculomegaly (VM).

METHODS

Single-center retrospective study 2013-2017; VM cases grouped into Early-onset VM (EVM; Diagnosis at/before 24 weeks) and Late-onset VM (LVM; Beyond 24 weeks). LVM cases had normal ventricle width measurement at mid-trimester scan. Infection serology, cytogenetics, MRI, sonographic follow-up, perinatal and neurodevelopmental outcomes were analyzed.

RESULTS

During the 5-year period, 64,662 women underwent an anomaly screening scan and 302 fetuses were identified with ventriculomegaly; 183 (60.6%) classified as early-onset and 119 (39.4%) LVM. The mean ventricular width was significantly higher in LVM cohort (14.1 mm vs 11.6 mm; p < .01). EVM cases were more often associated with structural anomalies (p < .05). Possible etiologies for EVM were aneuploidy and cerebral malformations like Absent Corpus Callosum, spina bifida, Dandy-Walker malformation, etc., whereas LVM followed aqueductal stenosis, hemorrhage, porencephaly, cerebral tumors, etc. Pregnancy outcomes were available for 251 cases. The pregnancy resulted in more live births in LVM group (87.4% vs 65.6%, p = < .01). Multivariate regression analysis demonstrated additional malformations (p < .0001, OR11.5 [95%CI: 4-35.2]), progression of VM (p = .004, OR 10.2 [95% CI: 2.1-52.3]) and severity of VM (OR 5.3 [95%CI: 0.8-37.7]) were significant predictors of Neurodevelopmental Impairment (NDI). Late gestation at diagnosis was more often associated with NDI (p = .063, OR2.4 [95%CI: 0.9-6.2]), although statistically insignificant.

CONCLUSIONS

EVM has a significantly different sonographic spectrum and outcomes compared to LVM. EVM is milder and associated with an increased risk of aneuploidy and structural malformations. LVM often occurs secondary to acquired brain lesions.

Imaging of fetal ventriculomegaly

Fetal ventriculomegaly is the most common central nervous system abnormality detected by prenatal imaging. It has a high association with other anomalies. Etiologies and prognoses for fetal ventriculomegaly range from normal outcomes to significant neurodevelopmental sequelae. In this paper, we review the development, terminology, pathogenesis, imaging and prognosis of fetal ventriculomegaly.

Role of prenatal magnetic resonance imaging in fetuses with isolated mild or moderate ventriculomegaly in the era of neurosonography: international multicenter study

OBJECTIVES

To assess the role of fetal magnetic resonance imaging (MRI) in detecting associated anomalies in fetuses presenting with mild or moderate isolated ventriculomegaly (VM) undergoing multiplanar ultrasound evaluation of the fetal brain.

METHODS

This was a multicenter, retrospective, cohort study involving 15 referral fetal medicine centers in Italy, the UK and Spain. Inclusion criteria were fetuses affected by isolated mild (ventricular atrial diameter, 10.0-11.9 mm) or moderate (ventricular atrial diameter, 12.0-14.9 mm) VM on ultrasound, defined as VM with normal karyotype and no other additional central nervous system (CNS) or extra-CNS anomalies on ultrasound, undergoing detailed assessment of the fetal brain using a multiplanar approach as suggested by the International Society of Ultrasound in Obstetrics and Gynecology guidelines for the fetal neurosonogram, followed by fetal MRI. The primary outcome of the study was to report the incidence of additional CNS anomalies detected exclusively on prenatal MRI and missed on ultrasound, while the secondary aim was to estimate the incidence of additional anomalies detected exclusively after birth and missed on prenatal imaging (ultrasound and MRI). Subgroup analysis according to gestational age at MRI (< 24 vs ≥ 24 weeks), laterality of VM (unilateral vs bilateral) and severity of dilatation (mild vs moderate VM) were also performed.

RESULTS

Five hundred and fifty-six fetuses with a prenatal diagnosis of isolated mild or moderate VM on ultrasound were included in the analysis. Additional structural anomalies were detected on prenatal MRI and missed on ultrasound in 5.4% (95% CI, 3.8-7.6%) of cases. When considering the type of anomaly, supratentorial intracranial hemorrhage was detected on MRI in 26.7% of fetuses, while polymicrogyria and lissencephaly were detected in 20.0% and 13.3% of cases, respectively. Hypoplasia of the corpus callosum was detected on MRI in 6.7% of cases, while dysgenesis was detected in 3.3%. Fetuses with an associated anomaly detected only on MRI were more likely to have moderate than mild VM (60.0% vs 17.7%; P < 0.001), while there was no significant difference in the proportion of cases with bilateral VM between the two groups (P = 0.2). Logistic regression analysis showed that lower maternal body mass index (adjusted odds ratio (aOR), 0.85 (95% CI, 0.7-0.99); P = 0.030), the presence of moderate VM (aOR, 5.8 (95% CI, 2.6-13.4); P < 0.001) and gestational age at MRI ≥ 24 weeks (aOR, 4.1 (95% CI, 1.1-15.3); P = 0.038) were associated independently with the probability of detecting an associated anomaly on MRI. Associated anomalies were detected exclusively at birth and missed on prenatal imaging in 3.8% of cases.

CONCLUSIONS

The incidence of an associated fetal anomaly missed on ultrasound and detected only on fetal MRI in fetuses with isolated mild or moderate VM undergoing neurosonography is lower than that reported previously. The large majority of these anomalies are difficult to detect on ultrasound. The findings from this study support the practice of MRI assessment in every fetus with a prenatal diagnosis of VM, although parents can be reassured of the low risk of an associated anomaly when VM is isolated on neurosonography. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Global and Regional Changes in Cortical Development Assessed by MRI in Fetuses with Isolated Nonsevere Ventriculomegaly Correlate with Neonatal Neurobehavior

BACKGROUND AND PURPOSE

Fetuses with isolated nonsevere ventriculomegaly (INSVM) are at risk of presenting neurodevelopmental delay. However, the currently used clinical parameters are insufficient to select cases with high risk and determine whether subtle changes in brain development are present and might be a risk factor. The aim of this study was to perform a comprehensive evaluation of cortical development in INSVM by magnetic resonance (MR) imaging and assess its association with neonatal neurobehavior.

MATERIALS AND METHODS

Thirty-two INSVM fetuses and 29 healthy controls between 26-28 weeks of gestation were evaluated using MR imaging. We compared sulci and fissure depth, cortical maturation grading of specific areas and sulci and volumes of different brain regions obtained from 3D brain reconstruction of cases and controls. Neonatal outcome was assessed by using the Neonatal Behavioral Assessment Scale at a mean of 4 ± 2 weeks after birth.

RESULTS

Fetuses with INSVM showed less profound and underdeveloped sulcation, including the Sylvian fissure (mean depth: controls 16.8 ± 1.9 mm, versus INSVM 16.0 ± 1.6 mm; P = .01), and reduced global cortical grading (mean score: controls 42.9 ± 10.2 mm, versus INSVM: 37.8 ± 9.9 mm; P = .01). Fetuses with isolated nonsevere ventriculomegaly showed a mean global increase of gray matter volume (controls, 276.8 ± 46.0 ×10 mm³, versus INSVM 277.5 ± 49.3 ×10 mm³, P = .01), but decreased mean cortical volume in the frontal lobe (left: controls, 53.2 ± 8.8 ×10 mm³, versus INSVM 52.4 ± 5.4 ×10 mm³; P = < .01). Sulcal depth and brain volumes were significantly associated with the Neonatal Behavioral Assessment Scale severity (P = .005, Nagelkerke R² = 0.732).

CONCLUSIONS

INSVM fetuses showed differences in cortical development, including regions far from the lateral ventricles, that are associated with neonatal neurobehavior. These results suggest the possible use of these parameters to identify cases at higher risk of altered neurodevelopment.

Significance of isolated borderline ventriculomegaly

PURPOSE

Foetal ventriculomegaly (VM) is one of the most commonly diagnosed brain abnormalities. The aims of this study were to assess cases with isolated VM, describe the prenatal course and assess short- and long-term follow-up at the age of 2 years.

METHODS

We performed a retrospective analysis from our prenatal data base and included all children that were prenatally diagnosed with VM in our unit between 2008 and 2013 (n = 250). Prenatal management, postnatal outcome and neurologic development at the age of 2 years were evaluated.

RESULTS

A total of 106 children were born at our institution and were diagnosed prenatally with isolated borderline VM. A total of 1.9% (n = 2/106) was transferred to the neonatal unit. A total of 0.9% (n = 1/106) showed abnormal findings in postnatal brain ultrasound. A total of 1.9% (n = 2/106) showed mild neurologic abnormalities after birth, but none had to be seen by a neuropediatrician. At the follow-up at 2 years, 2.5% (n = 1/40) had an insertion of a shunt.

CONCLUSION

Based on our analysis, the majority of isolated borderline VM do not show short- or long-term neurological abnormalities. However, all cases of VM should be referred to a detailed prenatal ultrasound exam by a specialist.

Neurodevelopmental disorder in children believed to have isolated mild ventriculomegaly prenatally

OBJECTIVE

To estimate the prevalence of specific neurodevelopmental disorders in children believed to have isolated mild ventriculomegaly (IMV) prenatally in the second trimester of pregnancy, in order to optimize the counseling process.

METHODS

This was a nationwide registry-based study including all singleton pregnancies that had first- and second-trimester ultrasound scans in the period 1^st January 2008 to 1^st October 2014, identified in the Danish Fetal Medicine Database and local clinical databases in Denmark. All fetuses diagnosed prenatally with IMV (measurement of the atrium of the lateral ventricles, 10.0-15.0 mm) between 18 and 22 weeks' gestation were followed up in national patient registers until the age of 2-7 years. Information was obtained on the diagnoses of intellectual disability, cerebral palsy, autism spectrum disorder, epilepsy and impaired psychomotor development. Neurodevelopmental disorders were compared between those with postnatally confirmed IMV and a reference population of children in the same age range.

RESULTS

Of a cohort of 292 046 fetuses, 133 were found to have apparent IMV on the second-trimester scan for fetal malformations. In 11 cases, long-term follow-up was not possible owing to termination of pregnancy, spontaneous miscarriage, neonatal death or loss to follow-up. Of the 122 liveborn children followed up until 2-7 years, 15 were identified as having an additional abnormality while 107 were confirmed postnatally to have IMV. Of these 107 children, the diagnosis of a neurodevelopmental disorder was registered in six (5.6%), corresponding to an odds ratio of 2.64 (95% CI, 1.16-6.02), as compared with the reference population. The diagnoses were autism spectrum disorder, epilepsy and impaired psychomotor development. None of these 107 children was diagnosed with intellectual disability or cerebral palsy.

CONCLUSIONS

Our results show that a confirmed diagnosis of IMV was associated with an increased risk of a neurodevelopmental disorder, as compared with the reference population, but the absolute risk was low and there were no cases of intellectual disability or cerebral palsy. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Role of magnetic resonance imaging in fetuses with mild or moderate ventriculomegaly in the era of fetal neurosonography: systematic review and meta-analysis

OBJECTIVES

To report the rate of additional central nervous system (CNS) anomalies detected exclusively on prenatal magnetic resonance imaging (MRI) in fetuses diagnosed with isolated mild or moderate ventriculomegaly (VM) on ultrasound, according to the type of ultrasound protocol adopted (dedicated neurosonography vs standard assessment of the fetal brain), and to explore whether the diagnostic performance of fetal MRI in detecting such anomalies is affected by gestational age at examination and laterality and degree of ventricular dilatation.

METHODS

MEDLINE, EMBASE, CINAHL and Clinicaltrials.gov were searched for studies reporting on the prenatal MRI assessment of fetuses diagnosed with isolated mild or moderate VM (ventricular dilatation of 10-15 mm) on ultrasound. Additional anomalies detected only on MRI were classified as callosal, septal, posterior fossa, white matter, intraventricular hemorrhage, cortical, periventricular heterotopia, periventricular cysts or complex malformations. The rate of additional anomalies was compared between fetuses diagnosed on dedicated neurosonography, defined as a detailed assessment of the fetal brain, according to the International Society of Ultrasound in Obstetrics and Gynecology guidelines, and those diagnosed on standard fetal brain assessment. The rate of additional CNS anomalies missed on prenatal MRI and detected only at birth was calculated and compared between fetuses that had early (at or before 24 weeks' gestation) and those that had late (after 24 weeks) MRI. Subanalysis was performed according to the laterality (uni- vs bilateral) and degree (mild vs moderate, defined as ventricular dilatation of 10-12 and 13-15 mm, respectively) of ventricular dilatation. Whether MRI assessment led to a significant change in prenatal management was explored. Random-effects meta-analysis of proportions was used.

RESULTS

Sixteen studies (1159 fetuses) were included in the systematic review. Overall, MRI detected an anomaly not identified on ultrasound in 10.0% (95% CI, 6.2-14.5%) of fetuses. However, when stratifying the analysis according to the type of ultrasound assessment, the rate of associated anomalies detected only on MRI was 5.0% (95% CI, 3.0-7.0%) when dedicated neurosonography was performed compared with 16.8% (95% CI, 8.3-27.6%) in cases that underwent a standard assessment of the fetal brain in the axial plane. The overall rate of an additional anomaly detected only at birth and missed on prenatal MRI was 0.9% (95% CI, 0.04-1.5%) (I² , 0%). There was no difference in the rate of an associated anomaly detected only after birth when fetal MRI was carried out before, compared with after, 24 weeks of gestation (P = 0.265). The risk of detecting an associated CNS abnormality on MRI was higher in fetuses with moderate than in those with mild VM (odds ratio, 8.1 (95% CI, 2.3-29.0); P = 0.001), while there was no difference in those presenting with bilateral, compared with unilateral, dilatation (P = 0.333). Finally, a significant change in perinatal management, mainly termination of pregnancy owing to parental request, following MRI detection of an associated anomaly, was observed in 2.9% (95% CI, 0.01-9.8%) of fetuses undergoing dedicated neurosonography compared with 5.1% (95% CI, 3.2-7.5%) of those having standard assessment.

CONCLUSIONS

In fetuses undergoing dedicated neurosonography, the rate of a CNS anomaly detected exclusively on MRI is lower than that reported previously. Early MRI has an excellent diagnostic performance in identifying additional CNS anomalies, although the findings from this review suggest that MRI performed in the third trimester may be associated with a better detection rate for some types of anomaly, such as cortical, white matter and intracranial hemorrhagic anomalies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Is fetal magnetic resonance imaging indicated in patients with isolated ventriculomegaly?

OBJECTIVE

Ventriculomegaly is one of the most common anomalies encountered at obstetric ultrasound and it necessitates follow up. Fetal magnetic resonance imaging (MRI) can be used to confirm the ultrasound diagnose or to detect additional anomalies. Aim of this study is to assess follow up and management of fetal ventriculomegaly shown by ultrasound, and to evaluate additional diagnostic contribution of MRI.

STUDY DESIGN

This study was conducted retrospectively including 89 patients who had fetal MRI subsequent to ultrasound diagnose of ventriculomegaly in between 2011-2017. Medical records of patients were investigated and accompanying anomalies, congenital infection, chromosomal examination, degree and progression of ventriculomegaly, neonatal imaging and diagnose, and neurodevelopmental findings on follow up were evaluated. Patients were classified in two groups as isolated and nonisolated ventriculomegaly, and subgroups mild, moderate, severe were formed according to their findings. SPSS 23.0 programme was used for statistical analysis.

RESULTS

Ultrasound and following MRI was performed in a range of 18-35^th gestational weeks, diagnoses were isolated ventriculomegaly for 56 patients and nonisolated ventriculomegaly for 33 patients. Progression and neurodevelopmental delay was higher in severe nonisolated ventriculomegaly group. There was not significant contribution of MRI in the follow up of isolated ventriculomegaly (p < 0.001), and diagnostic imaging findings declined in neonatal period with proceeding normal neurodevelopment in 92.7% of patients followed with diagnosis of isolated ventriculomegaly.

CONCLUSION

When isolated ventriculomegaly is detected, ultrasound performed by an experienced team is mostly sufficient. MRI can be used in suspicious cases or when ventriculomegaly progresses.

Current Controversies in Prenatal Diagnosis 1: Should MRI be performed on all fetuses with mild ventriculomegaly?

A ventricular diameter of 10 mm correlates with more than two standard deviations of the normal and hence is qualified as ventriculomegaly. The relevance of this is dependent on whether there are associated infectious, genetic, or structural problems. The chance for neurodevelopmental delay in isolated ventriculomegaly less than 15 mm is 7.9% (4.7-11.1), and less if it is unilateral. It can be further divided in mild (10-12) or moderate (13-15), though this is not widely accepted. As part of the workup, structural assessment today may include ultrasound or magnetic resonance imaging, or both. Discussants agreed that the diagnostic performance of both methods is as good as the expertise with which the images are acquired and interpreted. Discussants agreed that when the initial neurosonogram is normal, the likelihood of finding significant findings on MRI is low. Nevertheless, some anomalies may only be picked up or better worked out by fetal MRI. In utero follow-up is advocated, as progression may indicate a poorer outcome, and some conditions are only obvious late in pregnancy. Most benefit for future patients is expected from appropriate training in prenatal neuroimaging.

Mild ventriculomegaly from fetal consultation to neurodevelopmental assessment: A single center experience and review of the literature

OBJECTIVE

The aim of our study was to determine the outcome of fetuses with isolated mild ventriculomegaly, with prenatal imaging work-up, prenatal consultation, delivery and clinical follow-up performed in a single tertiary referring center.

METHODS

Fetuses with isolated and non-progressive mild ventriculomegaly (10-15 mm) were included in the study. Inclusion criteria were as follows: singleton pregnancies, normal chromosomal analysis, normal serological evaluation of TORCH, fetal ultrasound and MRI excluding additional CNS or extra-CNS malformations. The prenatal consultation consisted in discussing the prognosis of ventriculomegaly, according to the literature. The postnatal follow-up protocol included a neuroradiological investigation (cranial ultrasound or MRI), neurological and pediatric examinations. The Griffiths Scales were used to assess the neurodevelopmental outcome.

RESULTS

Thirty newborns were included in follow-up. The postnatal neuroradiological investigations confirmed the ventriculomegaly as an isolated finding in all cases except one. Nineteen children were available for formal neurodevelopmental testing. In our case series, 93.3% of the children had a favorable outcome or mild anomalies. Two children (6.6%) with mild ventriculomegaly were diagnosed as having rare genetic conditions. The Griffiths developmental quotients were normal (mean General Quotient 98.3) at the latest assessment (mean age 20.8 months) in all but one case.

DISCUSSION

Most children in our case series had a favorable outcome, as described in the literature. Even though a large quantity of data is now available on ventriculomegaly, fetal consultation remains challenging and requires caution. The diagnostic work-up of pregnancies diagnosed with mild ventriculomegaly must be very meticulous and include TORCH evaluation, microarray, serial ultrasounds to exclude progression, and a fetal MRI. However, despite accurate screening, there are more complex conditions in which ventriculomegaly can be the only non-specific finding in fetal life, making postnatal follow up mandatory.

Evaluation of choroid plexus with fetal magnetic resonance imaging: What happens in ventriculomegaly?

OBJECTIVES

Diagnosis of ventriculomegaly (VM) and identification of choroid plexus (CP) can be challenging with fetal magnetic resonance imaging (MRI). Our aim is to create an adjunct method for supporting the diagnosis of VM by investigating the CP-ventricular wall separation distance in fetuses with and without VM (nV) with fetal MRI.

METHODS

T2-weighted fetal MRIs of 154 fetuses were retrospectively evaluated. The CP separation was defined as the distance between the medial wall of the dependent ventricle and distal tip of the CP glomus. The measurement was performed at the same plane with the dependent ventricle measurement by two blinded readers.

RESULTS

41 fetuses with VM (mean gestational age 27 (19-35 weeks), and 44 nV fetuses (mean gestational age 28 (20-39 weeks) were included. Interobserver reliability was excellent for ventricle diameters (R = 0.99, confidence interval (CI) 95%) and the separation of CP (R = 0.98, CI 95%). Mean distance of CP separation was 10.7 mm ± 4.2 mm and 3.0 ± 1.6 mm in VM and nV fetuses, respectively (p < 0.001). The distance of CP separation to differentiate VM cases was 6.5 mm (sensitivity: 0.98, specificity: 0.98). Separation of CP was correlated to ventricle diameter in cases with (R = 0.674) and without VM (R = 0.805). For the cut-off value >0.65 cm for the distance between the medial wall of the dependent ventricle and the medial border of choroid plexus sensitivity is 97.56, specificity 95.45, positive predictive value (PPV) 95.20, negative predictive value (NPV) 97.70, and likelihood ratio (LR) (+) is 21.46.

CONCLUSION

Fetal CP can be efficiently evaluated with MRI, and the increase of CP-ventricular wall separation distance in correlation with the ventricle diameter is a reliable sign in the diagnosis of fetal VM.

Antenatal ultrasound value in risk calculation for Autism Spectrum Disorder: A systematic review to support future research

There is a growing research interest on the antenatal features of children with neurodevelopmental disorders. Indeed, it has been proved that the neurodevelopment is, at least partly, affected by processes occurring in fetal life and that the early neurodevelopmental disorders identification is essential to optimize long-term outcomes. This systematic review aims to summarize findings on antenatal ultrasound data, which are or might be considered early risk indexes of postnatal social impairments. We conducted systematic searches in Pubmed and PsychINFO databases to identify studies including fetal ultrasound measurements and postnatal neurodevelopmental outcome assessment. The bibliographic search included 3203 articles but after the assessment of the eligibility conducted by two independent researchers, only 26 studies were selected. Some alterations in ultrasound antenatal measurements (such as biophysical data, nuchal thickness and enlargement of cerebral ventricles) have been associated to autism spectrum disorder. However, data are still limited, controversial and not specific. Reported data are here discussed to strongly support studies on fetuses at high risk for autism spectrum disorder.

Prenatal Evaluation, Imaging Features, and Neurodevelopmental Outcome of Prenatally Diagnosed Periventricular Pseudocysts

BACKGROUND AND PURPOSE

Periventricular pseudocysts are cystic cavities that lack the ependymal cell lining found in true cysts. The aim of this study was to characterize periventricular pseudocysts and related findings and their neurodevelopmental outcome.

MATERIALS AND METHODS

This was a retrospective study of periventricular pseudocysts detected prenatally on fetal MR imaging in 26 fetuses. The fetuses were divided into group A (n = 8), which included cases with isolated periventricular pseudocysts, and group B (n = 18), which included cases of periventricular pseudocysts with additional findings. Cases were further subdivided into connatal cysts and subependymal pseudocysts. Data collected included prenatal history, MR imaging features, sonographic follow-up, and neurodevelopmental outcome.

RESULTS

All cases in group A (n = 8) had a normal outcome. In group B (n = 18), 6 pregnancies were terminated and 2 had an abnormal outcome. Both cases with an abnormal outcome involved patients with subependymal pseudocysts. No significant association was found between the morphologic features on MR imaging and the neurodevelopmental outcome.

CONCLUSIONS

Neurodevelopmental outcome in cases of isolated periventricular pseudocysts detected prenatally appears to be normal. A detailed evaluation should be performed to rule out additional brain findings, chromosomal aberration, and fetal malformation. This evaluation should include the following: maternal TORCH status, detailed fetal sonographic anatomic evaluation, fetal echocardiogram, fetal brain MR imaging, amniocentesis and karyotyping/comparative genomic hybridization, and genetic counseling. Additional findings on MR imaging, including mild-to-moderate dilated ventricles, asymmetric ventricles, or T2 hyperintense signal in the white matter without other findings or major fetal abnormality, appear to be benign. Connatal cysts appear to be benign.

Fetal ventriculomegaly: Pregnancy outcomes and follow-ups in ten years

The aim of this study is to evaluate the pregnancy outcomes and prognoses for fetuses with ventriculomegaly. Two hundred and forty-one cases of fetuses with ventriculomegaly were included in this study. The subjects were divided into three groups according to their lateral ventricular width: "Mild Ventriculomegaly" (10 ‒ < 12 mm), "Moderate Ventriculomegaly" (12 ‒ < 15 mm) and "Severe Ventriculomegaly" (≥ 15 mm). Pediatric examination records and telephone interviews were conducted to track the outcomes of children until the age of 9 years. Eight-two cases were Isolated Ventriculomegaly (34.0%), while Non-Isolated Ventriculomegaly was found in 159 cases (66.0%). The pregnancy was terminated in 91 cases, and a higher abortion ratio was found in the NIVM (Non-Isolated Ventriculomegaly) group compared with the IVM (Isolated Ventriculomegaly) group. The fetuses were delivered in 150 cases, and four infants suffered deaths with NIVM. Of the surviving fetuses, 7 with IVM and 9 with NIVM showed significant abnormalities. The Mild and Moderate VM groups had more favorable prognoses compared with the Severe VM group. Regarding the outcomes and progression of lateral ventricular width, 1 out of 42 cases in the regressed group and 19 out of 108 cases in the stable group showed significant abnormalities. This study suggests that the degree and the progression of ventricular dilatation are main factors that affect pregnancy outcomes and prognoses.

Recommendations on routine mid-trimester anomaly scan

The purpose of this paper is to discuss the minimal requirements of the routine mid-trimester anomaly scan in Asian countries after taking into account various factors, including local circumstances, medical practice, guidelines, and availability of experienced sonographers and high-resolution ultrasound machines, which affect the prenatal detection rate of fetal anomalies. In general, a routine mid-trimester anomaly scan includes the assessment of the number of fetuses, fetal cardiac activity, size, anatomy, liquor and placental location. The most controversial issue is which fetal structures should at least be examined. We discussed the requirements of a basic routine scan, as well as the optional views, which can be obtained if feasible to improve the detection of fetal, placental or maternal abnormalities. Routine anomaly scan remains a clinical challenge.

Neurodevelopmental outcome in isolated mild fetal ventriculomegaly: systematic review and meta-analysis

OBJECTIVES

The finding of fetal ventriculomegaly is variably associated with other fetal abnormalities and, even when isolated, is thought to be linked to abnormal neurodevelopmental outcome. The aim of this study was to undertake a systematic review and meta-analysis of the current literature to assess the prevalence of neurodevelopmental delay in cases of isolated mild fetal ventriculomegaly, as well as the false-negative rate of prenatal imaging for the diagnosis of associated abnormalities in patients referred for isolated mild ventriculomegaly.

METHODS

Studies that assessed neurodevelopmental outcome in isolated ventriculomegaly were identified from a search of scientific databases. Studies that did not check for karyotype or that excluded cases of bilateral ventriculomegaly were not included in the analysis. Ventriculomegaly was defined as mild when the width of the ventricular atrium was between 10 and 15 mm. Cases in which an associated abnormality (abnormal karyotype, structural abnormality or fetal infection) was observed either before or after birth were not considered as part of the isolated group. Neurodevelopmental delay was defined as an abnormal quotient score, according to the test used.

RESULTS

The search yielded 961 possible citations; of these, 904 were excluded by review of the title or abstract as they did not meet the selection criteria. Full manuscripts were retrieved for 57 studies, and 20 were included in the review with a total of 699 cases of isolated mild ventriculomegaly. The overall prevalence of neurodevelopmental delay was 7.9% (95% CI, 4.7-11.1%). Of the 20 studies included in the systematic review, nine reported data on postnatal imaging, showing a prevalence of previously undiagnosed findings of 7.4% (95% CI, 3.1-11.8%).

CONCLUSIONS

The false-negative rate of prenatal imaging is 7.4% in apparently isolated fetal ventriculomegaly of ≤ 15 mm. The incidence of neurodevelopmental delay in truly isolated ventriculomegaly of ≤ 15 mm is 7.9%. As the latter rate is similar to that noted in the general population, large prospective cohort studies assessing the prevalence of childhood disability, rather than subtle neurodevelopmental delay, are required.

Evolution of fetal ventricular dilatation in relation to severity at first presentation

BACKGROUND

To assess the outcome of 360 cases of fetal ventriculomegaly in a tertiary referral center.

METHODS

Cases of fetal ventriculomegaly between June 1993 and December 2011 were identified from the departmental fetal database. The fetal medicine reports and obstetric notes were reviewed to ascertain the antenatal progression of the ventriculomegaly as well as the outcome of the pregnancy. Ventriculomegaly was defined by a lateral ventricular wall atrial measurement of greater than 10 mm. Cases were subdivided into mild (>10 to <12 mm), moderate (≥12 to <15 mm), and severe (≥15 mm). Termination of pregnancy was offered in cases where there were associated anomalies, aneuploidy, or the ventriculomegaly progressed.

RESULTS

Of the 360 cases, 189 were mild, 79 were moderate, and 92 were severe. Sixty-four percent of cases had associated anomalies. Forty-six percent of cases in the mild group and 26% in the moderate group resolved. Only one case in the severe group improved. The mean rate of progression in the mild group was 1.07 (SD 1.03) mm/week, whereas in the moderate group progression was at a mean rate of 1.41 (SD 0.77) mm/week. Progression of severe ventriculomegaly was significantly higher at a mean rate of 3.26 (SD 2.92) mm/week (p = 0.007).

CONCLUSIONS

The majority of fetuses with mild ventriculomegaly normalized, whereas the majority of moderate cases remained stable. The rate of progression of ventriculomegaly increased with severity. Fetuses with ventriculomegaly should be offered serial scans to allow the progression of ventriculomegaly to be ascertained with the option of late termination of pregnancy.

Clinical outcomes of mild isolated cerebral ventriculomegaly in the presence of other neurodevelopmental risk factors

OBJECTIVES

The purpose of this study was to evaluate neuropsychological test data in school-aged children whose fetal sonograms revealed mild isolated cerebral ventriculomegaly without asymmetry of the lateral ventricles.

METHODS

Nine of 52 children 6 years and older with sonographic evidence of mild isolated cerebral ventriculomegaly without asymmetry of the lateral ventricles were able to be recruited for follow-up school-aged neuropsychological testing. The children received a half-day battery of neuropsychological tests, including the Wechsler Abbreviated Scales of Intelligence; Beery-Buktenica Developmental Test of Visual Motor Integration, Fifth Edition; Wide Range Achievement Test, Fourth Edition; and Integrated Visual and Auditory Continuous Performance Test. Parents completed the Conners 3 Parent Short Form and the Personality Inventory for Children, Second Edition.

RESULTS

In this small group, other risk factors for neurodevelopmental disorders were often present, including preterm birth, perinatal hypoxia, and a family history of psychiatric disease or substance abuse. Within this sample, the proportion of children with a pattern of test results showing poorer nonverbal intelligence than verbal intelligence scores and poorer math than reading performance, as well as meeting criteria for a diagnosis of attention deficit/hyperactivity disorder, was higher than the basal rates of these problems among children in general.

CONCLUSIONS

Particularly given the complexity of various factors affecting neurodevelopment, follow-up neuropsychological evaluation is warranted in children with sonographic evidence of mild isolated cerebral ventriculomegaly without asymmetry of the lateral ventricle (eg, in the context of poor school performance).

Evolution of ventriculomegaly: comparison between foetal MR imaging and postnatal diagnostic imaging

PURPOSE

We evaluated the evolution of ventriculomegaly (VM) by comparing foetal magnetic resonance imaging (MRI) with postnatal transcranial ultrasonography (US) and/or encephalic MRI.

MATERIALS AND METHODS

Between January 2006 and April 2011, 70 foetuses with a mean gestational age of 28 weeks and 4 days (range, 18-36) weeks with VM on foetal MRI were assessed in this prospective study. Half-Fourier rapid acquisition with relaxation enhancement (RARE) T2-weighted, T1-weighted and diffusion-weighted (DWI) images along the three orthogonal planes according to the longitudinal axis of the mother, and subsequently of the foetal brain, were acquired. Quantitative image analysis included the transverse diameter of lateral ventricles in axial and coronal planes. Qualitative image analysis included searching for associated structural anomalies.

RESULTS

Thirty-four of 70 patients with a diagnosis of VM on foetal MRI underwent postnatal imaging. Twenty-five of those 34 (73%) had mild, four (12%) had moderate and five (15%) had severe VM on MRI. Normalisation of the diameter of lateral ventricles was observed in 16 of the 34 (47%) newborns. Among these 16, 13 (81%) had mild and three (19%) had moderate VM (two isolated and one associated VM). VM stabilisation was observed in 16 of the 34 (47%) babies. Among them, 11 (69%) had mild (eight isolated and three associated), one (6%) had moderate associated and four (25%) had severe associated VM. Progression from mild to severe (associated) VM was observed in two of the 34 (6%) babies.

CONCLUSIONS

The absence of associated anomalies and a mild VM are favourable prognostic factors in the evolution of VM.

Postnatal outcome of isolated, nonprogressive, mild borderline fetal ventriculomegaly

BACKGROUND

This study aimed to evaluate postnatal outcome of fetuses affected by nonprogressive, isolated, mild (≥10 and ≤12 mm) borderline ventriculomegaly (BVM).

METHODS

We studied 25 consecutive fetuses with BMV and evaluated patients' characteristic, ultrasonographic findings, and the neurodevelopmental outcome at age ≥24 months.

RESULTS

The mean gestational age at diagnosis was 23.84 ± 5.02 weeks (min-max; 17-34 weeks). In 16 cases, BVM was bilateral (16/25, 64 %), 4 left sided (4/25, 16 %), and 5 right sided (5/25, 20 %). Fourteen cases were males (14/25, 56 %), and 11 cases were females (11/25, 44 %). In two cases, ventriculomegaly was regressed 4 weeks after the initial diagnosis (2/25, 8 %), and in the remaining cases, ventriculomegaly persisted between initial measurement and 12 mm. The mean age of the infant at the time of the neurodevelopmental evaluation was 45.9 months (24-77 months). The neurodevelopmental outcome at the mean age of 45.9 months was completely normal in 16 infants (16/25, 64 %). The remaining nine infants (9/25, 36 %) had mild degree of neuromotor developmental delay.

CONCLUSION

Prenatal counseling for isolated, nonprogressive, mild BVM should be mainly reassurance since it is not associated with severe neurodevelopmental delay. However, parents should be educated about the developmental milestone of children to observe and detect mild neurodevelopmental delay which can be associated with mild BVM.

Neuroimaging of ventriculomegaly in the fetal period

Fetal cerebral ventriculomegaly (VM) is defined as an enlargement of the lateral ventricles of the developing fetal brain. It is diagnosed when the width of one or both lateral ventricles, measured at the level of the atrium, is ≥10 mm. VM is defined as mild when the atrial width is 10-15 mm and severe when >15 mm. VM is a non-specific sonographic sign which is common to various pathological conditions. It is frequently associated with neural and extraneural anomalies. The rate of associated malformations is higher (≥60%) in severe VM and lower (about 40%) in cases of mild VM. When an abnormality is associated with severe VM the incidence of aneuploidies is high (>15%); in isolated mild VM the mean value of aneuploidy is 2.7%. The rate of infections in severe VM is 10-20%, in mild forms 1-5%. Since the prognosis in cases of VM depends mainly on the associated anomalies, a careful examination of the fetus, particularly of the brain, is mandatory. Magnetic resonance imaging can be a useful diagnostic tool complementary to ultrasound in order to recognize subtle brain anomalies, such as neuronal migration and proliferation disorders.

Cortical maturation in fetuses referred for 'isolated' mild ventriculomegaly: a longitudinal ultrasound assessment

OBJECTIVES

To compare cortical maturation between fetuses with isolated mild ventriculomegaly (IMV) and healthy fetuses, and to explore its potential prognostic value in IMV.

METHODS

This prospective study quantified cortical maturation by ultrasound in 24 fetuses with IMV and 46 healthy fetuses. Depth and grading the developmental pattern of the parieto-occipital fissure (POF), calcarine fissure (CF) and sylvian fissure, and grading the Sylvian fissure operculization at 23-25, 27-28 and 31-32 weeks gestation were determined.

RESULTS

At 23-25 and 27-28 gestational weeks, POF and CF mean depths were statistically lower in the IMV group. The POF and CF depth distribution had a normal distribution in the control group but displayed a bimodal distribution in the IMV group. IMV with progression of ventricular dilatation showed mean depth of CF lower than IMV in which ventriculomegaly regressed or remained stable. The sensitivity, specificity, positive predictive value and negative predictive value of a CF depth below the fifth percentile to predict progression of ventricular dilatation were, at 28 weeks, 100%, 88%, 67% and 100%, respectively.

CONCLUSIONS

Cortical fissure assessment by ultrasound allowed the differentiation of a subgroup of IMV fetuses with a higher risk of progression of ventricular dilatation.

Neonatal outcome of congenital ventriculomegaly

Enlargement of the cerebral ventricles (ventriculomegaly) occurs in 1-2 per 1000 live births. Ventriculomegaly is frequently diagnosed antenatally and hence the perinatologist is faced with counselling the prospective parents. This review considers the diagnosis, management and prognosis of this condition. A particular emphasis is placed on the outcome of isolated ventriculomegaly as these are commonly the most difficult to counsel antenatally.

Prevalence, natural history, and clinical outcome of mild to moderate ventriculomegaly

OBJECTIVE

To estimate the prevalence, associated anomalies, progression, and clinical outcome in fetuses diagnosed with mild to moderate ventriculomegaly at 18-24 weeks of pregnancy.

METHODS

This was a prospective population-based study from the North of England. Data were extracted from the U.K. Northern Congenital Abnormality Survey for cases identified during 1994-2008. Additional anomalies present were categorized according to European Surveillance of Congenital Anomalies guidelines. Differences between isolated and nonisolated ventriculomegaly were examined by either Fisher's exact test or Mann-Whitney U test. Changes in prevalence were examined by the χ² test for trend.

RESULTS

There were 355 cases of confirmed mild to moderate ventriculomegaly in singleton pregnancies at 18-24 weeks of gestation among 454,080 registered births, giving a total prevalence of 7.8 per 10,000 registered births (95% confidence interval [CI] 7.0-8.7). The minimum rate of chromosomal anomaly and trisomy 21 (including cases karyotyped postnatally) in isolated cases (ie, in which no other structural anomaly was identified prenatally) was 10.2% (95% CI 6.1-16.0) and 4.5% (95% CI 2.0-8.7), respectively. Additional structural anomalies were identified prenatally in 43.1% of cases. Among isolated cases, 61.9% (95% CI 53.3-70.0) resolved by the final prenatal scan (the majority by 24 weeks of gestation) and 10.7% (95% CI 6.4-16.6) were found to have "missed" structural anomalies after birth. The probability of an infant death for isolated ventriculomegaly was 3% (95% CI 0.8-7.6).

CONCLUSION

This register-based study on mild to moderate ventriculomegaly provides unique epidemiologic and outcome data. Information from this study should aid in counseling parents.

LEVEL OF EVIDENCE

III.

Prenatal neurologic anomalies: sonographic diagnosis and treatment

The low prevalence of fetal CNS anomalies results in a restricted level of exposure to, and limited experience for most obstetricians involved in, prenatal ultrasound. Sonographic guidelines for screening the fetal brain in a systematic way may increase the detection rate of fetal CNS anomalies, thus promoting correct referral to tertiary care centers offering patients a multidisciplinary approach to the condition. The aim of this review is to elaborate on the prenatal sonographic diagnosis and outcome of various CNS malformations. Detailed neurosonographic investigation has become available through high-resolution vaginal ultrasound probes and the development of a variety of 3-dimensional (3D) ultrasound modalities, such as ultrasound tomographic imaging. In addition, fetal magnetic resonance imaging is particularly helpful in the detection of gyration and neurulation anomalies, and disorders of the gray and white matter. Isolated mild ventriculomegaly is a rather common finding with good overall outcome. With an increasing diameter of the atria, however, and especially with the presence of associated malformations, long-term neurodevelopmental and behavioral outcome is disturbed in about 15% or more of cases. In view of recent developments in fetal therapy for neural tube defects, there is a clear need for a high level of ultrasound screening, work-up and counseling in tertiary care centers to identify those cases that might benefit from in utero intervention. The failure of prosencephalic midline induction and development results in midline defects ranging from alobar holoprosencephaly to isolated corpus callosum defects. The detection of callosal abnormaties is enhanced by 3D ultrasound, but counseling on neurodevelopmental outcome remains challenging. The Dandy-Walker spectrum includes isolated megacisterna magna, Blake's pouch cyst, hypoplasia of the vermis and Dandy-Walker malformation. Except for complete agenesis of the vermis associated with fourth ventricle cyst formation, data on long-term outcomes for the various conditions is largely lacking. Congenital cytomegalovirus (CMV) results in the highest incidence of children born with, or developing, long-term neurologic conditions. If proof of fetal infection has been delivered, microcephaly, cortical malformations, and intraparenchymal cysts show a strong correlation with poor outcome. Fetuses with CMV-related ultrasound abnormalities might benefit from maternal transplacental treatment. The aneurysm of the vein of Galen, a vascular malformation of the brain, often results in high cardiac output failure. After neonatal arterial embolization, survival is about 50% with normal neurologic development in 36% of cases. Over 50% of intracranial tumors are teratomata, presenting as fast-growing heterogeneous solid-cystic masses with calcifications. Most intracranial hemorrhages are related to the ventricular system, and prognosis is often poor, particularly in cases involving parenchymal and subdural bleeding. Proliferation disorders of the brain are often characterized by microcephaly. Their etiology is heterogeneous and prenatal diagnosis is often made late in gestation.

Volumetric and surface-based 3D MRI analyses of fetal isolated mild ventriculomegaly: brain morphometry in ventriculomegaly

Diagnosis of fetal isolated mild ventriculomegaly (IMVM) is the most common brain abnormality on prenatal ultrasound. We have set to identify potential alterations in brain development specific to IMVM in tissue volume and cortical and ventricular local surface curvature derived from in utero magnetic resonance imaging (MRI). Multislice 2D T2-weighted MRI were acquired from 32 fetuses (16 IMVM, 16 controls) between 22 and 25.5 gestational weeks. The images were motion-corrected and reconstructed into 3D volumes for volumetric and curvature analyses. The brain images were automatically segmented into cortical plate, cerebral mantle, deep gray nuclei, and ventricles. Volumes were compared between IMVM and control subjects. Surfaces were extracted from the segmentations for local mean surface curvature measurement on the inner cortical plate and the ventricles. Linear models were estimated for age-related and ventricular volume-associated changes in local curvature in both the inner cortical plate and ventricles. While ventricular volume was enlarged in IMVM, all other tissue volumes were not different from the control group. Ventricles increased in curvature with age along the atrium and anterior body. Increasing ventricular volume was associated with reduced curvature over most of the ventricular surface. The cortical plate changed in curvature with age at multiple sites of primary sulcal formation. Reduced cortical folding was detected near the parieto-occipital sulcus in IMVM subjects. While tissue volume appears to be preserved in brains with IMVM, cortical folding may be affected in regions where ventricles are dilated.

Neurodevelopmental outcome of 31 patients with borderline fetal ventriculomegaly

AIM

We present the neurodevelopmental outcome of patients with isolated borderline fetal ventriculomegaly.

METHODS

The present study was carried out at the Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul University in July-December 2010. Prenatal second trimester detailed ultrasound examinations were performed by obstetricians at the Prenatal Diagnosis Department of Istanbul Medical School, and 31 consecutive patients aged 8-33 months have been included in the study. Four patients with atrial diameters of over 15 mm and three patients with central nervous system development anomalies were excluded from the study. In order to assess the neuromotor development of patients, neurologic examinations and the Bayley Scales of Infant Development (BSID-III) were used.

RESULTS

Nine patients were female (29%) and 22 were male (71%). In the postnatal period, tuberous sclerosis was found in one patient, Down syndrome in one, and equinovarus foot deformity in one. Atrial diameter was <12 mm in 18 patients and >12 mm in 13. Cranial ultrasounds done in the first postnatal month revealed persisting ventriculomegaly in nine patients. The two patients who scored significantly low in all areas on the Bayley Scales of Infant Development were the patients with Down syndrome and tuberous sclerosis. The one scoring low in the motor area was the patient with the equinovarus foot deformity. The BSID-III scores of the patients whose prenatal ventricle diameter was <12 mm were within normal limits. The four patients showing slight developmental delay were the ones whose cranial ultrasound in the first postnatal month showed persisting ventriculomegaly.

CONCLUSION

In patients with borderline fetal ventriculomegaly, atrial diameter being more than 12 mm, the condition persisting in the first postnatal month and the presence of accompanying syndromes and malformations all constitute clear risk factors for neurodevelopmental outcome.

Mid-term neurodevelopmental outcome in isolated mild ventriculomegaly diagnosed in fetal life

OBJECTIVE

To analyze mid-term neurodevelopment outcome in children with isolated mild ventriculomegaly (VM) ≤12 mm diagnosed in fetal life, using the Battelle Developmental Inventory Screening Test (BDIST).

METHODS

86 cases of mild VM were identified. 68 were excluded due to: other cerebral anomalies (n = 40), extra-cerebral anomalies (n = 3), chromosomal defects (n = 4), dysmorphic syndromes (n = 4), congenital infections (n = 2), termination of pregnancy (n = 9), stillbirth (n = 2) and incomplete follow-up (n = 4). 18 cases (range 1-8 years) of isolated mild VM were included for analysis. Seven neurodevelopment domains were assessed by BDIST.

RESULTS

Routine neuropediatrical evaluation detected neurological disorders in five children (28%; 3 with language impairment, one left hemiparesis and one intellectual retardation). BDIST showed some degree of neurodevelopmental delay in higher proportions: 66% in social-personal skills, 56% in gross motor skills, 39% in adaptive behavior and 28% in fine motor skills. Communicative and cognitive areas were the least affected (11 and 22% had moderate-to-severe involvement, respectively). A general trend towards worse outcomes was observed in the group of ≥4 years, although significant differences were only found for gross motor skills.

CONCLUSION

Subtle neurological delays may appear during the infant period in fetuses prenatally diagnosed of isolated mild VM. In consequence, adequate measures should be established for early detection and treatment.

Ultrasound and MRI of fetuses with ventriculomegaly: can cortical development be used to predict postnatal outcome?

OBJECTIVE

The purpose of this study was to assess the conspicuity of brain cortical maturation with sonography and MRI of fetuses referred because of ventriculomegaly and to determine whether sulcal visualization can be used to predict postnatal outcome.

SUBJECTS AND METHODS

Women with 374 fetuses referred because of ventriculomegaly underwent sonography and MRI. Four to six radiologists rated visualization of 19 fissures or sulci. Majority opinion regarding sulcal visualization was compared among fetuses categorized by CNS abnormality: normal, isolated ventriculomegaly, and ventriculomegaly with additional CNS abnormalities. Live-born infants were categorized as having normal or abnormal development. Logistic regression analysis was used to correlate sulcal visualization and postnatal development. A subanalysis was performed with fetuses who had been classified prenatally as having a normal brain or isolated ventriculomegaly.

RESULTS

Cortical sulci were visualized more frequently and at an earlier gestational age with MRI than with ultrasound. In the entire cohort, the odds ratio of normal development ranged from 3.1 to 10.0 whenever the calcarine, parietooccipital, cingulate, superior temporal, precentral, or postcentral sulcus was seen on MR images. In fetuses categorized as having a normal brain or having isolated ventriculomegaly, the odds ratio of normal development ranged from 3.5 to 9.0 whenever the parietooccipital, cingulate, or superior temporal sulcus was seen.

CONCLUSION

Visualization of the sulci in fetal brains depends on the imaging modality used and the gestational age at imaging. Information regarding sulcal visualization may aid in counseling patients carrying fetuses with ventriculomegaly.

Prognosis of isolated mild to moderate fetal cerebral ventriculomegaly: a systematic review

AIMS

To ascertain risk of aneuploidy, infection and neurological abnormality for the fetus diagnosed with isolated mild (10.1-12.0 mm) to moderate (12.1-15.0 mm) cerebral ventriculomegaly and to compare the neurological outcome between symmetrical vs. asymmetrical and stable vs. progressive ventriculomegaly.

METHODS

A systematic review was conducted. Literature was identified by searching two bibliographical databases between 1980 and 2009 without language restrictions. The data extracted were inspected for heterogeneity. Overall rates and confidence intervals (CIs) for each prognostic factor were calculated. When comparative data existed, the odds ratio (OR) was calculated.

RESULTS

The search strategy yielded 2150 relevant citations of which 28 studies were included in the review. The overall rate of infection and chromosomal abnormality was 1.5 and 5% (95% CI 3, 7), respectively. The risk of neurological abnormality regardless of karyotype or infection screen was 14% (95% CI 10, 18) and this reduced to 12% (95% CI 9, 15) when both chromosomes and infection screen were normal. The risk of neurological abnormality was significantly lower in stable compared to progressive ventriculomegaly [OR 0.29 (95% CI 0.15, 0.58)]. No significant differences were detected when symmetrical vs. asymmetrical ventriculomegaly were compared [OR 0.91 (95% CI 0.34, 2.41)].

CONCLUSION

This systematic review provides the physician with some estimates of prognosis in cases of isolated mild to moderate ventriculomegaly.

Counseling in isolated mild fetal ventriculomegaly

In this Review we aim to provide up-to-date and evidence-based answers to the common questions regarding the diagnosis of isolated mild fetal ventriculomegaly (VM). A literature search was performed to identify all reports of antenatal VM in the English language literature. In addition, reference lists of articles identified using the search were scrutinized to further identify relevant articles. Fetal mild VM is commonly defined as a ventricular atrial width of 10.0-15.0 mm, and it is considered isolated if there are no associated ultrasound abnormalities. There is no good evidence to suggest that the width of the ventricular atria contributes to the risk of neurodevelopmental outcome in fetuses with mild VM. The most important prognostic factors are the association with other abnormalities that escape early detection and the progression of ventricular dilatation, which are reported to occur in about 13% and 16% of cases, respectively. Most infants with a prenatal diagnosis of isolated mild VM have normal neurological development at least in infancy. The rate of abnormal or delayed neurodevelopment in infancy is about 11%, and it is unclear whether this is higher than in the general population. Furthermore, the number of infants that develop a real handicap is unknown. There are limitations of existing studies of mild VM. Although they address many of the relevant questions regarding the prognosis and management of fetal isolated mild VM, there is a lack of good-quality postnatal follow-up studies. The resulting uncertainties make antenatal counseling for this abnormality difficult.

The neurocognitive outcome of mild isolated fetal ventriculomegaly verified by prenatal magnetic resonance imaging

OBJECTIVE

Neurocognitive outcome of preschool children, prenatal diagnosis of isolated mild ventriculomegaly compared with 2 control groups.

STUDY DESIGN

Case-controlled study at the University Hospital of Tel Aviv between October 1999 and December 2002. Study groups consisted of 12 children with bilateral isolated mild ventriculomegaly, and 16 children with unilateral isolated mild ventriculomegaly, mean age 4.4 years, prenatally diagnosed by both ultrasound and fetal magnetic resonanace imaging. Control groups consisted of 16 children with normal prenatal magnetic resonance imaging and 16 regular kindergarten children. A neurodevelopmental examination and the Kaufman Assessment Battery for Children were performed.

RESULTS

The neurodevelopmental and Kaufman scores were within normal range in the study groups. No significant differences between the study and control groups for most measures; however, Kaufman achievement score was significantly lower for the bilateral isolated mild ventriculomegaly group (P < .05) compared with the kindergarten children.

CONCLUSION

Preschool children with isolated mild ventriculomegaly performed within normal range compared with the controls. Nevertheless, a significant percentage of the children demonstrated developmental difficulties, lower achievement scores, justifying early school years follow-up.